Wire substrate and display device including the same

ABSTRACT

A wire substrate, a display device including a wire substrate, and a method of fabricating a wire substrate are disclosed. The display device comprises: a first base; and a first wiring layer disposed on the first base and comprising a conductive layer and a metal oxide layer stacked on the conductive layer, wherein the metal oxide layer comprises molybdenum (Mo), tantalum (Ta), and oxygen (O). The conductive layer includes a first metal layer on the first base, and a second metal layer between the first metal layer and the metal oxide layer. The second metal layer has a higher electrical conductivity than the first metal layer, and a thickness of the second metal layer is greater than a thickness of the first metal layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.15/906,991, filed Feb. 27, 2018, which claims priority to and thebenefit of Korean Patent Application No. 10-2017-0118647, filed on Sep.15, 2017, in the Korean Intellectual Property Office, the disclosure ofwhich is incorporated herein in its entirety by reference.

BACKGROUND 1. Field

The present disclosure relates to a wire substrate, a display deviceincluding the same, and method of fabricating a wire substrate.

2. Description of the Related Art

Display devices become more and more important as multimedia technologyevolves. Accordingly, a variety of display devices such asliquid-crystal display (LCD) devices and organic light-emitting diodedisplay (OLED) devices are currently utilized.

A display device may include a plurality of pixels representingdifferent colors to achieve color reproduction. In order to operate(i.e., control) the pixels of a display device individually and to havethem to display different colors, the display device may include drivingsignal wires for transmitting driving signals and various functionalelectrodes arranged in each of the pixels.

For example, driving signal wires and the like should have low electricresistance, high thermal stability and easy processability.

SUMMARY

As resolution of display devices ever increases, the area occupied by asingle pixel tends to decrease. In addition, as the degree ofintegration of the driving signal wires and the functional electrodesincreases, it is not easy to achieve a sufficient aperture ratio. Theaperture ratio is an important factor affecting the display quality,such as the brightness of the display device. In order to increase theaperture ratio of the display device, it may be contemplated to reducethe area occupied by the light-shielding member.

Unfortunately, if the area of the light-shielding member is reduced,wires and/or electrodes not covered by the light-shielding member mayreflect external light. The external light reflected by the wires or thelike may cause deterioration of the display quality, such as loweringthe contrast of the display device.

In view of the above, aspects of the present disclosure are directedtoward a display device with improved aperture ratio as well as improvedresolution and display quality by way of suppressing reflection ofexternal light.

Aspects of the present disclosure are also directed toward a wiresubstrate for display devices capable of improving resolution anddisplay quality.

Aspects of the present disclosure are also directed toward a method offabricating a wire substrate for display devices by which resolution anddisplay quality can be improved while defective etching can be reducedor prevented.

These and other aspects, embodiments and enhancements of the presentdisclosure will become apparent (e.g., immediately apparent) from theDetailed Description and Claims to follow, or may be learned by practiceof the presented embodiments.

According to an exemplary embodiment of the invention, a display deviceincludes: a first base; and a first wiring layer on the first base, thefirst wiring layer including a conductive metal layer and a metal oxidelayer stacked on one another, wherein the metal oxide layer includesMo_(x)Ta_(y)O_(z), wherein a content of tantalum is equal to or lessthan 2.0 at % (atomic percent) based on a total number of metal atoms(i.e., total number of metal atoms included in Mo_(x)Ta_(y)O_(z)).

In an exemplary embodiment, the conductive metal layer may be opaque andincludes a plurality of layers, and wherein a light reflectivity of themetal oxide layer may be smaller than a light reflectivity of a toplayer of the conductive metal layer in contact with the metal oxidelayer.

In an exemplary embodiment, the conductive metal layer may be betweenthe first base and the metal oxide layer, and wherein the metal oxidelayer may be a top layer of the first wiring layer.

In an exemplary embodiment, the conductive metal layer may be betweenthe first base and the metal oxide layer, and wherein a reflectivity ofthe first wiring layer with respect to light that may have a wavelengthof 550 nm and may be incident in a direction from an upper side to alower side is equal to or less than 6.0%.

In an exemplary embodiment, the conductive metal layer may include afirst metal layer on the first base, and a second metal layer betweenthe first metal layer and the metal oxide layer, wherein the secondmetal layer may have a higher electrical conductivity than the firstmetal layer.

In an exemplary embodiment, a thickness of the second metal layer may begreater than a thickness of the first metal layer.

In an exemplary embodiment, the first metal layer may include arefractory metal, and wherein the second metal layer may include copper,silver, aluminum, or an alloy thereof.

In an exemplary embodiment, the conductive metal layer may include afirst metal layer on the first base, and a second metal layer betweenthe first metal layer and the metal oxide layer, the second metal layerin contact with the first metal layer and the metal oxide layer, whereina thickness of the metal oxide layer may be greater than a thickness ofthe first metal layer and may be less than a thickness of the secondmetal layer, and wherein the thickness of the metal oxide layer mayrange from 300 to 550 Å.

In an exemplary embodiment, the conductive metal layer may include afirst metal layer on the first base, and a second metal layer betweenthe first metal layer and the metal oxide layer, the second metal layerin contact with the first metal layer, wherein a width of a surface ofthe first metal layer facing the second metal layer may be greater thana width of a surface of the second metal layer facing the first metallayer.

In an exemplary embodiment, a side wall of the metal oxide layer mayprotrude from a side wall of the conductive metal layer to form a tip.

In an exemplary embodiment, the display device may further include: asecond wiring layer partially overlapping with the first wiring layerand insulated from the first wiring layer, the second wiring layerincluding a conductive metal layer and a metal oxide layer stacked onone another, wherein the metal oxide layer of the second wiring layermay include Mo_(x)Ta_(y)O_(z), wherein a content of tantalum is equal toor less than 2.0 at % based on a total number of metal atoms (i.e.,total number of metal atoms included in Mo_(x)Ta_(y)O_(z)).

In an exemplary embodiment, the display device may further include: asemiconductor material layer between the first and second wiring layers,wherein the first base may be a glass substrate, and wherein theconductive metal layer of the first wiring layer may be directly on thefirst base.

In an exemplary embodiment, the first wiring layer may include a gatesignal wire extending in a first direction and a sustaining electrode,and wherein the second wiring layer may include a data signal wireextending in a second direction intersecting with the first direction.

In an exemplary embodiment, the conductive metal layer of the secondwiring layer may include a third metal layer and a fourth metal layerbetween the third metal layer and the metal oxide layer, wherein athickness of the first metal layer may be greater than a thickness ofthe third metal layer, and wherein a thickness of the second metal layermay be greater than a thickness of the fourth metal layer.

In an exemplary embodiment, a side wall of the metal oxide layer mayprotrude from a side wall of the conductive metal layer to form a tip ineach of the first wiring layer and the second wiring layer, and whereina length of the tip of the metal oxide layer in the second wiring layermay be greater than a length of the tip of the metal oxide layer of thefirst wiring layer.

In an exemplary embodiment, the display device may further include: alight-shielding member on the second wiring layer and having a lineshape extended in the first direction, wherein the sustaining electrodemay include a portion extended in the first direction and a portionextended in the second direction, wherein the gate signal wire maycompletely overlap with the light-shielding member, wherein thesustaining electrode may partially overlap with the light-shieldingmember, wherein at least a part of the portion extended in the seconddirection may not overlap the light-shielding member, and wherein thedata signal wire may partially overlap with the light-shielding member,wherein at least a part of the data signal wire may not overlap with thelight-shielding member.

According to an exemplary embodiment of the invention, a wire substrateinclude: a base; a conductive metal layer on the base; and a metal oxidelayer on the conductive metal layer, wherein the metal oxide layerincludes Mo_(x)Ta_(y)O_(z), wherein a content of tantalum is equal to orless than 2.0 at % based on a total number of metal atoms.

According to an exemplary embodiment of the invention, a method offabricating a wire substrate includes: forming a conductive metal layeron a base; forming a metal oxide layer on the conductive metal layer;forming a mask pattern on the metal oxide layer; and etching theconductive metal layer and the metal oxide layer altogether to form awire, wherein the metal oxide layer includes Mo_(x)Ta_(y)O_(z), whereina content of tantalum is equal to or less than 2.0 at % based on a totalnumber of metal atoms.

In an exemplary embodiment, the forming the metal oxide layer mayinclude forming the metal oxide layer by sputtering, wherein thesputtering may be carried out under an inert gas atmosphere, and whereina target of the sputtering may include Mo_(x)Ta_(y)O_(z), wherein acontent of tantalum may be equal to or less than 2.0 at % based on atotal number of metal atoms.

In an exemplary embodiment, the etching may include carrying out wetetching utilizing an etchant, wherein the etchant may include aperoxysulfate of 10.0 to 20.0% by weight, an organic acid of 0.1% to5.0% by weight, a fluorine-containing compound of 0.1 to 1.5% by weight,and a cyclic amine compound of 0.01 to 2.0% by weight, with the restbeing water.

According to an exemplary embodiment of the present disclosure, a wiringlayer includes Mo_(x)Ta_(y)O_(z) having a very low reflectivity withrespect to the visible wavelength band, so that it is possible tosuppress deterioration of display quality due to reflection of externallight.

In addition, the wiring layer itself has a very low reflectivity, suchthat the planar area occupied by the light-shielding member can bereduced, the aperture ratio of the display device can be improved, andthe resolution of the display device can be further increased.

According to an exemplary embodiment of the present disclosure, a methodof fabricating a wire substrate and a wire substrate can provide adisplay device having improved resolution and display quality.

It should be noted that effects of the present disclosure are notlimited to those described above and other effects of the presentdisclosure will be apparent to those skilled in the art from thefollowing descriptions.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the present disclosure willbecome more apparent by describing in more detail exemplary embodimentsthereof with reference to the accompanying drawings, in which:

FIG. 1 is an exploded, perspective view of a display device according toan exemplary embodiment of the present disclosure;

FIG. 2 is a layout diagram of some pixels of the display device shown inFIG. 1;

FIG. 3 is a cross-sectional view taken along the line III-III′ of FIG.2;

FIG. 4 is a cross-sectional view taken along the lines IVa-IVa′,IVb-IVb′ and IVc-IVc′ of FIG. 2;

FIG. 5 is a cross-sectional view of a first wiring layer and a secondwiring layer shown in FIG. 2;

FIGS. 6 to 13 are schematic illustrations showing a method offabricating a wire substrate according to an exemplary embodiment of thepresent disclosure;

FIG. 14 shows microscopic images of the stack patterns formed accordingto Experimental Examples 1 to 4;

FIG. 15 is a graph showing tip lengths of Mo_(x)Ta_(y)O_(z) layersaccording to Experimental Examples 1 to 4;

FIG. 16 is a graph showing the light reflectivity of the stack patternsaccording to Experimental Examples 1 to 4 measured in the visiblewavelength band;

FIGS. 17A to 17C show microscopic images according to ExperimentalExamples 5 to 13; and

FIG. 18 is a graph showing simulation results according to ExperimentalExample 14.

DETAILED DESCRIPTION

Features of the invention and methods of accomplishing the same may beunderstood more readily by reference to the following detaileddescription of preferred embodiments and the accompanying drawings. Theinvention may, however, be embodied in many different forms and shouldnot be construed as being limited to the embodiments set forth herein.Rather, these embodiments are provided so that this disclosure will bethorough and complete and will fully convey the concept of the inventionto those skilled in the art, and the invention will only be defined bythe appended claims, and equivalents thereof.

It will be understood that when an element or layer is referred to asbeing “on,” “connected to” or “coupled to” another element or layer, theelement or layer can be directly on, connected to or coupled to anotherelement or layer or intervening elements or layers may exist. Incontrast, when an element is referred to as being “directly on,”“directly connected to” or “directly coupled to” another element orlayer, there are no intervening elements or layers present. As usedherein, the term “connected” may refer to elements being physically,electrically and/or fluidly connected to each other.

Like numbers refer to like elements throughout. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

It will be understood that, although the terms first, second, third,etc., may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or sectionwithout departing from the teachings of the invention.

Spatially relative terms, such as “below,” “lower,” “under,” “above,”“upper” and the like, may be used herein for ease of description todescribe the relationship of one element or feature to anotherelement(s) or feature(s) as illustrated in the figures. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation, in addition tothe orientation depicted in the figures. For example, if the device inthe figures is turned over, elements described as “below” or “beneath”relative to other elements or features would then be oriented “above”relative to the other elements or features. Thus, the exemplary term“below” can encompass both an orientation of above and below. The devicemay be otherwise oriented (rotated 90 degrees or at other orientations)and the spatially relative descriptors used herein should be interpretedaccordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an” and “the” are intended to include the pluralforms as well, including “at least one,” unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises,” “comprising,” “includes” and/or “including,” when used inthis specification, specify the presence of stated features, integers,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof. The term “atleast one” is not to be construed as limiting “a” or “an.” The term “or”has the same meaning as the term “and/or.” As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

In the present specification, a first direction X is any direction in aplane, a second direction Y is a direction intersecting the firstdirection X in the plane, and a third direction Z is a directionperpendicular to the plane.

Hereinafter, exemplary embodiments of the present disclosure will bedescribed with reference to the accompanying drawings.

FIG. 1 is an exploded, perspective view of a display device according toan exemplary embodiment of the present disclosure.

Referring to FIG. 1, a display device 1 according to an exemplaryembodiment of the present disclosure includes a display panel 1 a and alight source unit 1 b for providing light to the display panel 1 a.

A plurality of pixels PXa and PXb may be defined on the display panel 1a such that the pixels PXa and PXb are extended in a first direction Xand a second direction Y to form a matrix when viewed from the top. Asused herein, a “pixel” refers to a single area defined by dividing adisplay area into sub-areas for color reproduction when viewed from thetop. A single pixel may represent a predetermined or set one of primarycolors. That is, a (e.g., one) pixel may be a minimum unit of thedisplay panel 1 a that can represent a color different from that ofanother pixel. The primary colors may include, but is not limited to,red, green and blue. As a non-limiting example, the first pixels PXa andthe second pixels PXb arranged in the first direction X may representdifferent colors.

The display panel 1 a may include driving signal wires such as aplurality of gate signal wires 210 extending in the first direction X,and a plurality of data signal wires 510 extending in the seconddirection Y and insulated from the gate signal wires 210. The gatesignal wires 210 and the data signal wires 510 may be connected todrivers to transmit the driving signals to the pixel electrode 600disposed in each of the plurality of pixels.

The light source unit 1 b may be disposed below the display panel 1 a toprovide light having a specific wavelength to the display panel 1 a. Thelight source unit 1 b may include light sources that emit light, and alight guide plate that guides the path of light provided from the lightsources so that light exits toward the display panel 1 a. The materialof the light guide plate is not particularly limited as long as it hashigh light transmittance. For example, it may be made of a glassmaterial, a quartz material, or a plastic material such as polyethyleneterephthalate, polycarbonate, etc.

The light sources may be light-emitting diodes (LEDs), organiclight-emitting diodes (OLEDs), or the like. In an exemplary embodiment,the light sources may emit light in the blue wavelength band or may emitlight of white color.

Although not shown in the drawings, one or more optical sheets may bedisposed between the display panel 1 a and the light source unit 1 b.The optical sheets may include one or more of a prism sheet, a diffusionsheet, a (reflective) polarizing sheet, a lenticular lens sheet, and amicro lens sheet. The optical sheets can improve the display quality ofthe display device 1 by modulating optical characteristics of lightprovided from the light source unit 1 b and traveling toward the displaypanel 1 a. For example, the optical sheets may condense light,diffuse/scatter light, or modulate polarization characteristics of thelight.

Hereinafter, the display panel 1 a according to the exemplary embodimentof the present disclosure will be described in more detail withreference to FIGS. 2 and 3.

FIG. 2 is a layout diagram of some pixels of the display device shown inFIG. 1, which shows a first wiring layer 200, a second wiring layer 500,a pixel electrode 600, a light-shielding member 700, and the like. FIG.3 is a cross-sectional view taken along the line III-III′ of FIG. 2.

Referring to FIGS. 1 to 3, the display panel 1 a according to theexemplary embodiment of the present disclosure may include a lowersubstrate 10 and an upper substrate 20 facing each other, and aliquid-crystal layer 30 interposed therebetween. The liquid-crystallayer 30 may be sealed by the lower substrate 10, the upper substrate 20and a sealing member for attaching them together. The lower substrate 10may be a wire substrate on which driving signal wires for driving thedisplay panel 1 a are arranged. The upper substrate 20 may be a colorconversion substrate on which a color conversion pattern is arranged.

The lower substrate 10 will be described first. The lower substrate 10may include a first base 110, a first wiring layer 200 disposed on thefirst base 110, a second wiring layer 500 disposed on the first wiringlayer 200, and a pixel electrode 600 disposed on the second wiring layer500.

The first base 110 may be a transparent insulating substrate. Forexample, the first base 110 may be a substrate made of a glass material,a quartz material, or a transparent plastic material. In some exemplaryembodiment of the present disclosure, the first base 110 may be flexiblesuch that the display device 1 may be a curved display device.

The first wiring layer 200 may be disposed on the first base 110. Thefirst wiring layer 200 may be disposed directly on the first base 110.In an exemplary embodiment, the first wiring layer 200 may include gatesignal wires 210 and sustaining electrodes 230. The gate signal wires210 and the sustaining electrodes 230 may be disposed on the same layer.For example, the gate signal wires 210 and the sustaining electrodes 230may have substantially the same structure and may be made ofsubstantially the same material. They may be formed simultaneously orconcurrently via a single process.

The gate signal wires 210 may extend generally in the first direction X.The gate signal wire 210 may deliver a gate driving signal provided froma gate driver to switching elements disposed in each of the pixels, suchas PXa and PXb. For example, the plurality of pixels arranged in thefirst direction X may share one gate signal wire 210. It is, however, tobe noted that this is merely illustrative.

A part of the gate signal wire 210 may form the gate electrode of theswitching element. For example, a part of the gate signal wire 210 mayserve as a control terminal of a first switching element Q1, a secondswitching element Q2 and a third switching element Q3, which will bedescribed in more detail later. In another exemplary embodiment, thecontrol terminal of the switching element may be formed such that itprotrudes from the gate signal wire 210.

The sustaining electrode 230 may be arranged such that it overlaps witha part of the second wiring layer 500 and/or a part of the pixelelectrode 600, which will be described in more detail later. Thesustaining electrode 230 may form a holding capacitor along with thesecond wiring layer 500, the pixel electrode 600 and a plurality ofdielectric layers disposed therebetween, which are disposed above thesustaining electrode 230. The holding capacitor can hold the voltageapplied to the pixel electrode 600 during one frame. The sustainingelectrode 230 may have an extended part in order to increase theoverlapping area with the second wiring layer 500 and the pixelelectrode 600. By doing so, the capacity of the holding capacitor can beincreased, and the voltage can be stably maintained during one frame.

In an exemplary embodiment, the sustaining electrode 230 may be disposedsuch that it partially overlaps with the edge of a first sub-pixelelectrode 610. When the first sub-pixel electrode 610 has a generallyrectangular shape, the sustaining electrode 230 may have a substantiallyrectangular band shape including portions 231 extending in the firstdirection X and portions 232 extending in the second direction Y.However, this is merely illustrative and the sustaining electrode 230may be modified in various suitable ways to form the holding capacitoralong with the second wiring layer 500 and the pixel electrode 600.

The first wiring layer 200 including the gate signal wire 210 and thesustaining electrode 230 may have a stack structure including aconductive metal layer and a metal oxide layer stacked on each other.The stack structure of the first wiring layer 200 will be describedlater in more detail with reference to FIGS. 4 and 5.

A first insulating layer 310 may be disposed on the entire surface ofthe first base 110 over the first wiring layer 200. The first insulatinglayer 310 may include an insulative material so that it insulateselements thereon from elements thereunder. The first insulating layer310 may be a gate insulating layer that insulates a control terminal(that is, a gate terminal) from a channel layer (i.e., active layer) ofthe first to third switching elements Q1 to Q3, which will be describedin more detail later. The first insulating layer 310 may include siliconnitride, silicon oxide, silicon oxynitride, etc.

An active layer 400 may be disposed on the first insulating layer 310.The active layer 400 may include a semiconductor material. For example,the active layer 400 may include amorphous silicon or polycrystallinesilicon, or may be made of an oxide semiconductor. A part of the activelayer 400 may form a channel layer of the switching element. Forexample, a part of the active layer 400 may serve as a channel of thefirst switching element Q1, the second switching element Q2 and thethird switching element Q3, which will be described in more detaillater, such that it may turn on/off the channel depending on the voltageapplied to the gate signal wire 210. In an exemplary embodiment, atleast a part of the active layer 400 may extend generally in the seconddirection Y and may be disposed to overlap with the data signal wire510.

The second wiring layer 500 may be disposed on the active layer 400. Inan exemplary embodiment, the second wiring layer 500 may include a datasignal wire 510, a source electrode layer 530 and a drain electrodelayer 550, and may further include a reference voltage wire 570. Thedata signal wire 510, the source electrode layer 530, the drainelectrode layer 550 and the reference voltage wire 570 may be disposedon the same layer. For example, the data signal wire 510, the sourceelectrode layer 530, the drain electrode layer 550 and the referencevoltage wire 570 may have substantially the same structure and may bemade of substantially the same material. They may be formedsimultaneously or concurrently via a single process.

The data signal wire 510 may extend generally in the second direction Y.The data signal wire 510 may deliver a data driving signal provided froma data driver to the switching elements disposed in each of the pixelsPXa and PXb. For example, the plurality of pixels arranged in the seconddirection Y may share one data signal wire 510. It is, however, to benoted that this is merely illustrative.

The source electrode layer 530 may include a first source electrode 531,a second source electrode 532, and a third source electrode 533. Thefirst source electrode 531, the second source electrode 532 and thethird source electrode 533 may serve as input terminals of the firstswitching element Q1, the second switching element Q2 and the thirdswitching element Q3, respectively.

The first source electrode 531 may protrude from the data signal wire510 without physical boundary with the data signal wire 510. The firstsource electrode 531 may be spaced apart from the first drain electrode551 above the gate signal wire 210 and the active layer 400.

The second source electrode 532 may protrude from the data signal wire510 without physical boundary with the data signal wire 510 and thefirst source electrode 531. The second source electrode 532 may bespaced apart from the second drain electrode 552 above the gate signalwire 210 and the active layer 400.

The third source electrode 533 may be extended from the second drainelectrode 552 without physical boundary with the second drain electrode552. The third source electrode 533 may be spaced apart from the thirddrain electrode 553 above the gate signal wire 210 and the active layer400.

The drain electrode layer 550 may include a first drain electrode 551, asecond drain electrode 552, and a third drain electrode 553. The firstdrain electrode 551, the second drain electrode 552 and the third drainelectrode 553 may serve as output terminals of the first switchingelement Q1, the second switching element Q2 and the third switchingelement Q3, respectively.

The first drain electrode 551 may be spaced apart from the first sourceelectrode 531 above the gate signal wire 210 and the active layer 400.The first drain electrode 551 may be electrically connected to the firstsub-pixel electrode 610 via the first contact hole H1.

The second drain electrode 552 may be spaced apart from the secondsource electrode 532 above the gate signal wire 210 and the active layer400. The second drain electrode 552 may be electrically connected to thesecond sub-pixel electrode 630 via the second contact hole H2. Inaddition, the second drain electrode 552 and the third source electrode553 may be formed as a single piece without physical boundarytherebetween.

The third drain electrode 553 may be spaced apart from the third sourceelectrode 533 above the gate signal wire 210 and the active layer 400.

The reference voltage wire 570 may extend generally in the seconddirection Y. For example, the part of the reference voltage wire 570extended in the second direction Y may overlap with a stem 601 of thepixel electrode 600, which will be described later. As the referencevoltage wire 570 overlaps with the stem 601 of the pixel electrode 600,it is possible to suppress the luminance degradation due to thereference voltage wire 570 penetrating through an opening. The referencevoltage wire 570 may be applied with a reference voltage. The referencevoltage will be described later along with the pixel electrode 600.

In an exemplary embodiment, a part of the reference voltage wire 570 maypartially form the third drain electrode 553. For example, the referencevoltage wire 570 to which the reference voltage is applied may alsoserve as an output terminal of the third switching element Q3. However,this is merely illustrative. In other exemplary embodiments, thereference voltage wire 570 may be physically separated from butelectrically connected to the third drain electrode 553.

The second wiring layer 500 such as the data signal wire 510, the sourceelectrode layer 530, the drain electrode layer 550 and the referencevoltage wire 570 may have a stack structure including a conductive metallayer and a metal oxide layer stacked on each other. The stack structureof the second wiring layer 500 will be described later in more detailwith reference to FIGS. 4 and 5.

A second insulating layer 330 may be disposed on the entire surface ofthe first base 110 over the second wiring layer 500. The secondinsulating layer 330 may be made of an insulative material. The secondinsulating layer 330 may insulate the second wiring layer 500 from thepixel electrode 600. The second insulating layer 330 may have astructure of a plurality of layers stacked on one another. For example,the second insulating layer 330 may have a double-layer structureincluding a protective layer 331 made of an inorganic material and aplanarization layer 332 made of an organic material. In addition, aplurality of contact holes may be formed in the second insulating layer330. For example, a first contact hole H1 may be formed by penetratingthe second insulating layer 330 to partially expose the first drainelectrode 551, and a second contact hole H2 may be formed by penetratingthe second insulating layer 330 to partially expose the second drainelectrode 552.

The pixel electrode 600 may be disposed on the second insulating layer330. The pixel electrode 600 may form an electric field in theliquid-crystal layer 30 together with a common electrode 900 to bedescribed later, to control the alignment of the liquid crystals (e.g.,liquid crystal molecules) 31 in the pixel. The pixel electrode 600 maybe disposed in each of the pixels and may receive voltage individually.The pixel electrode 600 may be a transparent electrode made of atransparent conductive material. Examples of the material for formingthe transparent electrode may include indium tin oxide (ITO) or indiumzinc oxide (IZO).

In an exemplary embodiment, the pixel electrode 600 in one pixel mayinclude a first sub-pixel electrode 610 and a second sub-pixel electrode630 spaced from each other. The area occupied by the first sub-pixelelectrode 610 may be smaller than the area occupied by the secondsub-pixel electrode 630 when viewed from the top.

The first sub-pixel electrode 610 and the second sub-pixel electrode 630may have a generally rectangular shape when viewed from the top and maybe pattern electrodes having divided domains (e.g., domain dividingmeans). For example, each of the first sub-pixel electrode 610 and thesecond sub-pixel electrode 630 may include a stem 601, a plurality ofbranches 602 extending from the stem 601, and a connecting portion 603extended from branches 602.

The stem 601 may be formed in a generally cross shape. The stem 601 mayoverlap with the reference voltage wire 570 extended generally in thesecond direction Y. The branches 602 may be extended radially from thecross-like stem 601 with an inclination, for example, approximately 45degrees. For example, each of the first sub-pixel electrode 610 and thesecond sub-pixel electrode 630 may have four domains that are divided bythe stem 601 and each have branches extended in different directions. Bydoing so, the liquid crystals can be controlled more efficiently, theviewing angle can be improved, and the brightness and response time ofthe display device 1 can be improved.

The connecting portion 603 of the first sub-pixel electrode 610 mayelectrically connect the first sub-pixel electrode 610 with the firstdrain electrode 551 via the first contact hole H1. The connectingportion 603 of the second sub-pixel electrode 630 may electricallyconnect the second sub-pixel electrode 630 with the second drainelectrode 552 via the second contact hole H2.

As described above, the first switching element Q1 to the thirdswitching element Q3 may share a single gate signal wire 210 and may becontrolled simultaneously. The data voltage supplied from the datasignal wire 510 may be applied to the first sub-pixel electrode 610 viathe first switching element Q1. On the other hand, the second drainelectrode 552 of the second switching element Q2 may be electricallyconnected to the reference voltage wire 570 via the third switchingelement Q3. Therefore, a set or predetermined voltage having a levelbetween the level of the data voltage provided from the data signal wire510 and the level of the reference voltage provided from the referencevoltage wire 570 may be applied to the second sub-pixel electrode 630.By doing so, the voltage applied to the second sub-pixel electrode 630may be smaller than the voltage applied to the first sub-pixel electrode610. By applying different voltages to the first sub-pixel electrode 610and the second sub-pixel electrode 630 disposed in one pixel, it ispossible to improve the side visibility of the display device 1.

Although FIG. 2 depicts that the edge of the first sub-pixel electrode610 overlaps with the sustaining electrode 230, in other exemplaryembodiments, the edge of the second sub-pixel electrode 630 may overlapwith the sustaining electrode 230, or both of the first sub-pixelelectrode 610 and the second sub-pixel electrode 630 may overlap withthe sustaining electrode 230.

Next, the upper substrate 20 will be described in more detail. The uppersubstrate 20 may include a second base 130, a light-shielding member 700disposed on a surface (lower surface in the drawing) of the second base130 facing the first base 110, a color conversion pattern 810 disposedon the light-shielding member 700, and a common electrode 900 disposedon the color conversion pattern 810.

The second base 130 may be a transparent substrate like the first base110. The first base 110 and the second base 130 may be made of eitherthe same material or different materials.

The light-shielding member 700 may be disposed on the second base 130.The light-shielding member 700 may be made of a material that can blocktransmission of light in the visible wavelength band. Thelight-shielding member 700 may be disposed to overlap with the firstswitching element Q1, the second switching element Q2 and the thirdswitching element Q3, thereby preventing or reducing unintended lightleakage.

In an exemplary embodiment, the light-shielding member 700 may have aline shape (e.g., a narrow strip) extending in the first direction X andmay overlap with the first to third switching elements Q1 to Q3. Thelight-shielding member 700 may or may not overlap with a part of thesustaining electrode 230, a part of the active layer 400 and a part ofthe data signal wire 510. Further, the light-shielding member 700 maycompletely overlap with the gate signal wire 210. In other words, thegate signal wire 210 may be completely covered by the light-shieldingmember 700. Although FIG. 2 (and the like) depicts an example where thelight-shielding member 700 is disposed on the upper substrate 20, inother embodiments, the light-shielding member 700 may be disposed on thelower substrate 10.

The color conversion pattern 810 may be disposed on the light-shieldingmember 700 so as to overlap with the pixel electrode 600. The colorconversion pattern 810 may be disposed at each of the pixels PXa andPXb. Light may have a specific wavelength band after it has passedthrough the color conversion pattern 810. Accordingly, different pixelsPXa and PXb of the display device 1 may represent different colors.

For example, the color conversion pattern 810 may be a color filtercontaining a colorant material such as a dye or pigment. The colorantmaterial may selectively absorb only a specific wavelength band ofincident light. The color conversion pattern 810 may absorb light of aspecific wavelength band of incident light and selectively transmitlight of another specific wavelength band.

As another example, the color conversion pattern 810 may be a wavelengthshifting member containing a wavelength shifting material such as aquantum dot material or a fluorescent material. The wavelength shiftingmaterial may convert or shift the peak wavelength of the incident lightto another specific peak wavelength. The color conversion pattern 810may absorb at least a part of the incident light to allow light having aspecific peak wavelength to exit.

An overcoat layer 830 may be disposed on the entire surface of thesecond base 130 over the color conversion pattern 810. The overcoatlayer 830 may provide a flat surface over a plurality of elementsdisposed on the second base 130, and the common electrode 900 may bedisposed on the overcoat layer 830.

On the overcoat layer 830, the common electrode 900 may be disposed. Thecommon electrode 900 may be a single piece formed across the pixels PXaand PXb such that a common voltage may be applied. The common electrode900 may be a transparent electrode like the pixel electrode 600.

Next, the liquid-crystal layer 30 will be described in more detail. Theliquid-crystal layer 30 may include liquid crystals (i.e., liquidcrystal molecules) 31 that are initially orientated. The liquid crystals31 may have a negative dielectric anisotropy and may be verticallyaligned in the initial state. The liquid crystals 31 may have apredetermined pretilt angle in the initially aligned state. When anelectric field is formed between the pixel electrode 600 and the commonelectrode 900, the liquid crystals 31 may be tilted in a specificdirection to change the polarization state of light passing through theliquid-crystal layer 30. In another embodiment, the liquid crystals 31may have a positive dielectric anisotropy and may be horizontallyaligned in the initial state, and when the electric field is formed, theliquid crystals 31 may rotate to change the polarization state of thelight.

Hereinafter, the first wiring layer 200 and the second wiring layer 500according to the exemplary embodiment of the present disclosure will bedescribed in more detail with reference to FIGS. 4 and 5.

FIG. 4 is a cross-sectional view taken along lines IVa-IVa′, IVb-IVb′and IVc-IVc′ of FIG. 2. Specifically, the cross-sectional view takenalong the line IVa-IVa′ shows the sustaining electrode 230 (e.g., theportion 232) and the gate signal wire 210. The cross-sectional viewtaken along the line IVb-IVb′ shows the reference voltage wire 570 andthe data signal wire 510 in the area where they do not overlap with thelight-shielding member 700. The cross-sectional view taken along theline IVc-IVc′ shows the reference voltage wire 570 and the data signalwire 510 in the area where they overlap with the light-shielding member700. FIG. 5 is a cross-sectional view of the first wiring layer 200 andthe second wiring layer 500 shown in FIG. 2.

Referring to FIGS. 1 to 5, each of the first wiring layer 200 and thesecond wiring layer 500 may have the conductive metal layers 201 and 501and the metal oxide layers 202 and 502 stacked on one another,respectively, to form the stack structure. Although FIG. 4 (and thelike) depicts both of the first wiring layer 200 and the second wiringlayer 500 as including the conductive metal layers 201 and 501 and themetal oxide layers 202 and 502, respectively, one of the first wiringlayer 200 and the second wiring layer 500 may not include the metaloxide layers 202 and 502.

First, the first wiring layer 200 will be described in more detail. Thefirst wiring layer 200 may include a first conductive metal layer 201disposed on the first base 110 and a first metal oxide layer 202disposed on the first conductive metal layer 201.

The first conductive metal layer 201 may have a structure in which twoor more layers are stacked on one another. For example, the firstconductive metal layer 201 may include a first metal layer 201 a and asecond metal layer 201 b stacked on each other.

The first metal layer 201 a may include a metal material having anexcellent adhesion to the first base 110 and may be disposed directly onthe first base 110. For example, the first metal layer 201 a may includea refractory metal having excellent processability. As used herein, theterm “refractory metal” refers to a metal or an alloy having a meltingpoint higher than 1500° C. Examples of the refractory metal may includeniobium (Nb), vanadium (V), tantalum (Ta), titanium (Ti), zirconium(Zr), hafnium (Hf), molybdenum (Mo), rhenium (Re), tungsten (W), and thelike. As a non-limiting example, the first metal layer 201 a may be atitanium layer made solely of titanium or may be a single layerincluding an alloy. The first metal layer 201 a may exhibit opaqueproperties.

The second metal layer 201 b may be disposed directly on the first metallayer 201 a. The second metal layer 201 b may be the top layer of thefirst conductive metal layer 201 having the structure of a plurality oflayers stacked on one another. The second metal layer 201 b may includea metal material having a low specific resistance and an excellentelectrical conductivity. The electrical conductivity of the second metallayer 201 b may be greater than the electrical conductivity of the firstmetal layer 201 a. For example, the second metal layer 201 b may includecopper (Cu), silver (Ag), aluminum (Al) or an alloy thereof. The secondmetal layer 201 b may exhibit opaque properties. As a non-limitingexample, the second metal layer 201 b may be a copper layer made solelyof copper or may be a single layer including an alloy.

As a non-limiting example, the first metal layer 201 a may be made of ametal material having a refractive index higher than that of the secondmetal layer 201 b. For example, the first metal layer 201 a may have arefractive index of approximately 1.5 to 2.8 with respect to light inthe visible wavelength band, and the second metal layer 201 b may have arefractive index of approximately 0.20 to 1.2 with respect to light inthe visible wavelength band. In one embodiment, the first metal layer201 a may have a refractive index of approximately 2.3 to 2.6, forexample, approximately 2.5 with respect to light having the wavelengthof 550 nm. The second metal layer 201 b may have a refractive index ofapproximately 0.8 to 1.2, for example, approximately 1.0 with respect tolight having the wavelength of 550 nm. It is, however, to be understoodthat this is merely illustrative.

The thickness t_(201b) of the second metal layer 201 b may be larger(i.e., greater) than the thickness t_(201a) of the first metal layer 201a. For example, the thickness t_(201a) of the first metal layer 201 amay be approximately 50 to 500 Å, for example, approximately 100 to 300Å. The thickness t_(201b) of the second metal layer 201 b may beapproximately 1,000 to 20,000 Å, for example, approximately 5,000 to10,000 Å.

In an exemplary embodiment, the sidewall of the first metal layer 201 amay protrude from the sidewall of the second metal layer 201 b to form atip T1. The tip T1 of the first metal layer 201 a can improve thestability of the second metal layer 201 b. For example, the width W_(1a)of the surface (upper surface in the drawing) of the first metal layer201 a facing the second metal layer 201 b may be larger (i.e., greater)than the width W_(1b) of the surface (lower surface in the drawing) ofthe second metal layer 201 b facing the first metal layer 201 a. Theupper limit of the length L1 of the tip of the first metal layer 201 amay be approximately 0.5 μm or less. If the length L1 of the tip islarger than 0.5 μm, there may arise a problem that the off-current ofthe switching element increases remarkably.

The first metal oxide layer 202 may be a single layer disposed directlyon the second metal layer 201 b. The first metal oxide layer 202 mayinclude a material having a higher light absorptivity and a lower lightreflectivity than the first conductive metal layer 201. The first metaloxide layer 202 may have a higher light absorptivity and a lower lightreflectivity than (e.g., each of) the first metal layer 201 a and thesecond metal layer 201 b.

In an exemplary embodiment, the first metal oxide layer 202 may includeMo_(x)Ta_(y)O_(z). The content (i.e., the amount) of tantalum (Ta) amongthe metal atoms in the first metal oxide layer 202 may be equal to orless than approximately 2.0 at % (atomic percent), approximately 1.9 at%, approximately 1.8 at %, approximately 1.7 at %, approximately 1.6 at%, approximately 1.5 at %, approximately 1.4 at %, approximately 1.3 at%, approximately 1.2 at %, approximately 1.1 at % or approximately 1.0at %. That is, the upper limit of the ratio of y to (x+y), i.e.,(y/(x+y)) may be approximately 0.02. If the content of tantalum isgreater than 2.0 at %, the light reflectivity of the first metal oxidelayer 202 with respect to the visible wavelength band may increase. Thereflectivity of the first metal oxide layer 202 may be the smallest whenthe content of tantalum lies between approximately 1.0 at % and 2.0 at%, although the present invention is not limited thereto. If the contentof tantalum is larger (e.g., greater) than 2.0 at %, the etchingstability may be lowered and thus it may be difficult to control theetched surface. For example, a tip T2 of the first metal oxide layer 202described below may become too long.

The lower limit of the content of tantalum among the metal atoms in thefirst metal oxide layer 202 may be, but is not limited to, approximately0.3 at % or more, or approximately 0.5 at % or more in light of theprocessability. Here, the lower limit of the ratio of y to (x+y), i.e.,(y/(x+y)) may be approximately 0.003 or greater. If the content oftantalum is less than 0.3 at %, the metal oxide layer may be etched bywater and thus may be unstable.

In some embodiment, a ratio of z to x, i.e., (z/x) may be approximately2.0 to 3.0, or 2.2 to 2.3.

As a non-limiting example, the light absorptivity of the first metaloxide layer 202 having the thickness of 500 Å may be equal to or greaterthan approximately 40%, approximately 45%, approximately 50%,approximately 55%, or approximately 60%. For example, the first metaloxide layer 202 having the thickness of 500 Å itself may have, but isnot limited to, a light reflectivity of approximately 25% to 40%, and alight transmittance of approximately 15% to 25%. For example, theextinction coefficient k of the first metal oxide layer 202 with respectto light in the visible wavelength band may range from approximately0.40 to 0.90.

In addition, the refractive index of the first metal oxide layer 202 maybe larger than that of the second metal layer 201 b. For example, therefractive index of the first metal oxide layer 202 with respect tolight in the visible wavelength band may be approximately 2.2 to 2.6.For example, the refractive index of the first metal oxide layer 202with respect to light having the wavelength of 550 nm may beapproximately 2.2 to 2.3.

The thickness t₂₀₂ of the first metal oxide layer 202 may be greaterthan the thickness t_(201a) of the first metal layer 201 a and less thanthe thickness t_(201b) of the second metal layer 201 b. In addition, thefirst metal oxide layer 202 may have a thickness of kλ/4, where k is anodd number, such that it can exhibit destructive interference withrespect to light in the visible wavelength band. For example, thethickness t₂₀₂ of the first metal oxide layer 202 may be approximately100 to 2,000 Å, approximately 300 to 550 Å, or 400 Å. When the thicknesst₂₀₂ of the first metal oxide layer 202 lies between 300 Å and 550 Å,the light reflectivity can be effectively decreased, although thepresent invention is not limited thereto.

In an exemplary embodiment, the sidewall of the first metal oxide layer202 may protrude from the sidewall of the second metal layer 201 b toform the tip T2. The tip T2 of the first metal oxide layer 202 disposedabove the first wiring layer 200 can serve to decrease the reflectivity.For example, the width W_(1c) of the surface (lower surface in thedrawings) of the first metal oxide layer 202 facing the second metallayer 201 b may be greater than the width W_(1d) of the surface (uppersurface in the drawings) of the second metal layer 201 b facing thefirst metal oxide layer 202. The upper limit of the length L2 of the tipof the first metal oxide layer 202 may be approximately 0.80 μm or less.If the length L2 of the tip is larger than 0.80 μm, it may disturb thesubsequent processes after forming the first wiring layer 200. Forexample, when the length L2 of the tip of the first metal oxide layer202 is less than 0.80 μm, the density of the first insulating layer 310can be improved. The lower limit of the length L2 of the tip may beapproximately 0.03 μm or more. If the length L2 of the tip of the firstmetal oxide layer 202 is larger than 0.03 μm, the reflectivity of thefirst wiring layer 200 can be effectively reduced.

On the other hand, the first metal oxide layer 202 may be disposed atthe top of the first wiring layer 200. It is possible to effectivelyreduce the reflectivity of the first wiring layer 200 by disposing thefirst metal oxide layer 202 having a large light absorptivity and havinga thickness exhibiting destructive interference at the top of the firstwiring layer 200. The reflectivity of the first wiring layer 200 withrespect to light that has the wavelength of 550 nm and is incident fromthe first metal oxide layer 202 (from above in the drawings) toward thefirst wiring layer 200 may be equal to or less than approximately 6.0%,approximately 5.5%, approximately 5.4%, approximately 5.3%,approximately 5.2%, approximately 5.1%, or approximately 5.0%, althoughthe present invention is not limited thereto. Further, the first wiringlayer 200 includes the first conductive metal layer 201 so that it canimpart excellent electrical conductivity and can work (e.g., function)as a wire as well as an electrode.

As described above, the first wiring layer 200 may include the gatesignal wire 210 and the sustaining electrode 230.

In an exemplary embodiment, the gate signal wire 210 extended in thefirst direction X may completely overlap with the light-shielding member700 having a line shape and extended in the first direction X. In otherwords, the gate signal wire 210 may be completely covered by thelight-shielding member 700.

In addition, the sustaining electrode 230 may partially overlap with thelight-shielding member 700. For example, when the sustaining electrode230 includes a portion extended in the first direction X and a portionextended in the second direction Y, at least a part of the portionextended in the second direction Y may not be overlapped with thelight-shielding member 700 but may be exposed to external light.

The first wiring layer 200 according to the exemplary embodiment of thepresent disclosure may have a very low reflectivity with respect tolight in the visible wavelength band, and thus the area occupied by thelight-shielding member 700 can be reduced when viewed from the top. Thedisplay device 1 according to the exemplary embodiment of the presentdisclosure can exhibit good contrast ratio even though thelight-shielding member 700 is extended only in the first direction X anddoes not have the portion extended in the second direction Y, althoughthe present invention is not limited thereto. In addition, it is alsopossible to eliminate the light-shielding member 700 extended in thesecond direction Y at the boundary between the pixels PXa and PXbadjacent in the first direction X so as to improve the aperture ratio ofthe display device 1.

Subsequently, the second wiring layer 500 will be described in moredetail. The second wiring layer 500 may include a second conductivemetal layer 501 disposed above the first wiring layer 200 such that itis insulated therefrom, and a second metal oxide layer 502 disposed onthe second conductive metal layer 501. For example, the first insulatinglayer 310 may be disposed between the first wiring layer 200 and thesecond wiring layer 500.

The second conductive metal layer 501 may have a structure in which twoor more layers are stacked on one another. For example, the secondconductive metal layer 501 may include a third metal layer 501 a and afourth metal layer 501 b.

In an exemplary embodiment of the present disclosure, the thicknesst_(501a) of the third metal layer 501 a of the second wiring layer 500may be equal to or less than the thickness t_(201a) of the first metallayer 201 a of the first wiring layer 200. If the first base 110 is madeof a glass material or the like, the adhesion and processability of thefirst wiring layer 200 can be improved by forming the first metal layer201 a of the first wiring layer 200 so that it has a sufficientthickness t_(201a). In addition, the thickness t_(501b) of the fourthmetal layer 501 b of the second wiring layer 500 may be equal to or lessthan the thickness t_(201b) of the second metal layer 201 b of the firstwiring layer 200. The resistance of the first wiring layer 200 can bereduced and the deterioration and stability can be improved by formingthe second metal layer 201 b of the first wiring layer 200 that isextended longer so that it has a sufficient thickness t_(201b).

The material, functionality, refractive index, shape and the like of thethird metal layer 501 a and the fourth metal layer 501 b of the secondwiring layer 500 may be substantially identical to those of the firstmetal layer 201 a and the second metal layer 201 b of the first wiringlayer 200, therefore, the redundant description will be omitted.

In addition, the second metal oxide layer 502 may be disposed directlyon the fourth metal layer 501 b. The second metal oxide layer 502 mayinclude a material having a higher light absorptivity and a lower lightreflectivity than the second conductive metal layer 501. In an exemplaryembodiment, the second metal oxide layer 502 may includeMo_(x)Ta_(y)O_(z). The upper limit of the content of tantalum among themetal atoms in the second metal oxide layer 502 may be approximately 2.0at % or less. In addition, the lower limit of the content of tantalumamong the metal atoms in the second metal oxide layer 502 may be, but isnot limited to, approximately 0.3 at % or more.

The sidewall of the second metal oxide layer 502 may protrude from thesidewall of the fourth metal layer 501 b to form a tip T3. The tip T3 ofthe second metal oxide layer 502 disposed above the second wiring layer500 can serve to decrease the reflectivity. For example, the widthW_(2c) of the surface (lower surface in the drawings) of the secondmetal oxide layer 502 facing the fourth metal layer 501 b may be greaterthan the width W_(2d) of the surface (upper surface in the drawings) ofthe fourth metal layer 501 b facing the second metal oxide layer 502.

In an exemplary embodiment, the length L3 of the tip of the second metaloxide layer 502 of the second wiring layer 500 may be greater than thelength L2 of the tip of the first metal oxide layer 202 of the firstwiring layer 200. By forming the length L3 of the tip of the secondmetal oxide layer 502 of the second wiring layer 500 long enough,excellent low reflection change can be achieve. In addition, by formingthe length L2 of the tip of the first metal oxide layer 202 of the firstwiring layer 200 shorter, the processability of the first insulatinglayer 310 can be achieved. For example, the upper limit of the length L3of the tip of the second metal oxide layer 502 of the second wiringlayer 500 may be approximately 1.00 μm or less. The lower limit of thelength L3 of the tip may be approximately 0.03 μm or more.

The material, functionality, light absorptivity, refractive index,thickness and the like of the second metal oxide layer 502 of the secondwiring layer 500 may be substantially identical to the first metal oxidelayer 202 of the first wiring layer 200, therefore, the redundantdescription will be omitted.

On the other hand, the second metal oxide layer 502 may be disposed atthe top of the second wiring layer 500. It is possible to effectivelyreduce the reflectivity of the second wiring layer 500 by disposing thesecond metal oxide layer 502 having a large light absorptivity andhaving a thickness exhibiting destructive interference at the top of thesecond wiring layer 500. The reflectivity of the second wiring layer 500with respect to light that has the wavelength of 550 nm and is incidentfrom the second metal oxide layer 502 (from above in the drawings)toward the second wiring layer 500 may be equal to or less thanapproximately 6.0%, approximately 5.5%, approximately 5.4%,approximately 5.3%, approximately 5.2%, approximately 5.1%, orapproximately 5.0%, although the present invention is not limitedthereto. Further, the second wiring layer 500 includes the secondconductive metal layer 501 so that it can impart excellent electricalconductivity and can work as a wire as well as an electrode.

In an exemplary embodiment, an active layer 400 may be disposed betweenthe second wiring layer 500 and the first insulating layer 310. When thesecond conductive metal layer 501 comes in contact with the active layer400, the third metal layer 501 a may serve as a barrier for preventing(or substantially preventing) ions in the fourth metal layer 501 b fromdiffusing into the active layer 400. In some embodiments, if the activelayer 400 is made of amorphous silicon or the like, an ohmic contactlayer may be further disposed between the second wiring layer 500 andthe active layer 400. The ohmic contact layer may include n+hydrogenatedamorphous silicon highly doped with n-type impurities or may includesilicide. The ohmic contact layer can reduce the contact resistancebetween the second wiring layer 500 and the active layer 400.

As described above, the second wiring layer 500 may include the datasignal wiring 510, and may further include the reference voltage wiring570.

In an exemplary embodiment, the data signal wire 510 and the referencevoltage wire 570 extended in the second direction Y may partiallyoverlap with the light-shielding member 700. For example, at least apart of the data signal wire 510 and the reference voltage wire 570 maynot be overlapped with the light-shielding member 700 but may be exposedto external light.

The second wiring layer 500 according to the exemplary embodiment of thepresent disclosure may have a very low reflectivity with respect tolight in the visible wavelength band, and thus the area occupied by thelight-shielding member 700 can be reduced when viewed from the top. Thedisplay device 1 according to the exemplary embodiment of the presentdisclosure can exhibit good contrast ratio even though thelight-shielding member 700 is extended only in the first direction X anddoes not have the portion extended in the second direction Y (e.g., thelight-shielding member 700 has a narrow strip shape extending in thefirst direction X and has a very small width in the second direction Y),although the present invention is not limited thereto. In addition, itis also possible to eliminate the light-shielding member 700 extended inthe second direction Y (e.g., there is no light-shielding member 700) atthe boundary between the pixels PXa and PXb adjacent in the firstdirection X so as to improve the aperture ratio of the display device 1.

Hereinafter, a method of fabricating a wire substrate according toexemplary embodiments of the present disclosure will be described inmore detail.

FIGS. 6 to 13 are views for illustrating a method of fabricating a wiresubstrate according to an exemplary embodiment of the presentdisclosure, which are cross-sectional views with respect to FIG. 4.

Referring first to FIG. 6, a first conductive metal layer 201′ is formedon a first base 110. In an exemplary embodiment, the first conductivemetal layer 201′ may have a structure including one or more layersstacked on one another. The first conductive metal layer 201′ mayinclude a first metal layer 201 a′ directly disposed on the first base110 and a second metal layer 201 b′ disposed directly on the first metallayer 201 a′. The method of forming the first metal layer 201 a′ and thesecond metal layer 201 b′ may include, but is not limited to, adeposition method such as vacuum deposition and sputtering. The firstmetal layer 201 a′ and the second metal layer 201 b′ are substantiallythe same as the first metal layer 201 a and the second metal layer 201 bdescribed above, and thus redundant description will be omitted.

Referring next to FIG. 7, a first metal oxide layer 202′ is formed onthe first conductive metal layer 201′. The forming of the first metaloxide layer 202′ may include depositing the first metal oxide layer 202′directly on the second metal layer 201 b′ utilizing sputtering. Thesputtering process may be DC sputtering utilizing a DC voltage source.

The sputtering process may be carried out under an inert gas atmosphere.For example, the sputtering process may be carried out under an argonatmosphere containing no oxygen. In addition, the target material TM forthe sputtering process may include Mo_(x)Ta_(y)O_(z). The upper limit ofthe content of tantalum among the metal atoms in the target material TMmay be approximately 2.0 at % or less. The atomic ratio in the firstmetal oxide layer 202′ can be precisely controlled by utilizing thetarget material TM in the oxide state to form the first metal oxidelayer 202′. For example, the composition of the target material TM forthe sputtering may be substantially identical to the composition of thefirst metal oxide layer 202′ formed after the sputtering. That is, byperforming the sputtering utilizing the target material TM having adesired composition, it is possible to precisely control the compositionof the first metal oxide layer 202′.

The thickness t₂₀₂ of the deposited first metal oxide layer 202′ may beapproximately 100 to 2,000 Å, approximately 300 to 550 Å, orapproximately 400 Å. When the thickness t₂₀₂ of the deposited firstmetal oxide layer 202′ lies between 300 Å and 550 Å, the lightreflectivity can be decreased effectively, although the presentinvention is not limited thereto.

Subsequently, referring to FIG. 8, a first mask pattern MP1 is formed onthe first metal oxide layer 202′.

In an exemplary embodiment, the forming of the first mask pattern MP1may include forming a layer of photosensitive material on the firstmetal oxide layer 202′, partially irradiating light onto the layer ofphotosensitive material utilizing a mask (e.g., a first mask), andapplying a developer to develop the first mask pattern MP1.

The layer of photosensitive material may include a material that isresponsive to light. For example, the layer of photosensitive materialmay include a negative photosensitive material or a positivephotosensitive material.

In the exposed portion where light is irradiated via the opening of themask, polymers are at least partially cured in the negativephotosensitive material, such that they become insoluble. Accordingly,the non-exposed portion may be removed by the developer. As a result,the residual photosensitive material pattern may have a shape conformingto the reversed light-shielding pattern of the mask, i.e., a shapeconfirming to the opening pattern.

In the exposed portion where light is irradiated via the opening of themask, bondings between polymers (e.g., between polymer molecules) are atleast partially disconnected in the positive photosensitive material,such that it becomes soluble. Accordingly, the exposed portion may beremoved by the developer. As a result, the residual photosensitivematerial pattern may have a shape conforming to the light-shieldingpattern of the mask.

Subsequently, referring to FIG. 9, the first metal layer 201 a′, thesecond metal layer 201 b′ and the first metal oxide layer 202′ areetched altogether utilizing the first mask pattern MP1 as an etch mask.In an exemplary embodiment, the etching of the first metal layer 201 a′,the second metal layer 201 b′ and the first metal oxide layer 202′ mayinclude patterning the first metal layer 201 a′, the second metal layer201 b′ and the first metal oxide layer 202′ via a wet etching process toform the first metal layer 201 a, the second metal layer 201 b and thefirst metal oxide layer 202.

Wet etching has advantages over dry etching in that it is simpler andhas better etching uniformity. For example, the etching of the firstmetal layer 201 a′, the second metal layer 201 b′ and the first metaloxide layer 202′ may include applying an etchant.

The etchant may have reactivity to all of the first metal layer 201 a′,the second metal layer 201 b′ and the first metal oxide layer 202′. Inan exemplary embodiment, the etchant may include peroxysulfate orpersulfate of approximately 10.0 to 20.0% by weight (weight percent), anorganic acid or salt thereof of approximately 0.1 to 5.0% by weight, afluorine-containing compound of approximately 0.1 to 1.5% by weight, anda cyclic amine compound of approximately 0.01 to 2.0% by weight, withthe rest (i.e., the balance) being water.

The persulfate may be a main component for etching the first metal oxidelayer 202′ and the second metal layer 201 b′. Examples of peroxysulfatemay include peroxymonosulfate peroxodisulfate. The peroxysulfate may bein the form of a salt such as ammonium and sodium.

The fluorine-containing compound may be a main component for etching thefirst metal oxide layer 202′ and the first metal layer 201 a′. Thefluorine-containing compound is not particularly limited as long as itcan generate fluorine ions or polyatomic fluorine ions. For example, thefluorine-containing compound may include ammonium fluoride, sodiumfluoride, ammonium bifluoride, sodium bifluoride, and potassiumbifluoride.

The organic acid or salt thereof and the cyclic amine compound canimprove the etching stability of the first metal layer 201 a, the secondmetal layer 201 b and the first metal oxide layer 202. Examples of theorganic acid include acetic acid and the like, and examples of thecyclic amine compound include an imidazole-based compound and atetrazole-based compound.

In this manner, the first wiring layer 200 can be formed. The specificshape, arrangement and physical properties of the first wiring layer 200have been described above, therefore, the redundant description will beomitted.

Subsequently, referring to FIGS. 10 and 11, the residual mask pattern isremoved. Then, a first insulating layer 310 and an active layer 400′ areformed on the first wiring layer 200. In doing so, the active layer 400′may not be patterned yet. The first insulating layer 310 and the activelayer 400′ (which is substantially the same as the active layer 400)have been described above, therefore, the redundant description will beomitted.

Subsequently, referring to FIG. 12, a second conductive metal layer 501′and a second metal oxide layer 502′ are formed on the active layer 400′.In an exemplary embodiment, the second conductive metal layer 501′ mayhave a stack structure in which one or more layers are stacked on oneanother. The second conductive metal layer 501′ may include a thirdmetal layer 501 a′ disposed directly on the active layer 400′ and afourth metal layer 501 b′ disposed directly on the third metal layer 501a′. In addition, the second metal oxide layer 502′ may be formed bysputtering. The sputtering process has been described above withreference to FIG. 6, therefore, the redundant description will beomitted.

Still referring to FIG. 12, a second mask pattern MP2 is formed on thesecond metal oxide layer 502′. In an exemplary embodiment, the formingof the second mask pattern MP2 may include forming a layer ofphotosensitive material on the second metal oxide layer 502′, partiallyirradiating light onto the layer of photosensitive material utilizing amask (e.g., a second mask), and applying a developer to develop thesecond mask pattern MP2. In some embodiments, the exposure mask forforming the second mask pattern MP2 may be a halftone mask or a slitmask. The thickness of the second mask pattern MP2 near the channelregion of the switching element can be partially controlled by utilizinga halftone mask or the like.

Subsequently, referring to FIG. 13, the active layer 400′, the thirdmetal layer 501 a′, the fourth metal layer 501 b′ and the second metaloxide layer 502′ are etched altogether by utilizing the second maskpattern MP2 as an etching mask. In an exemplary embodiment, the etchingthe active layer 400′, the third metal layer 501 a′, the fourth metallayer 501 b′ and the second metal oxide layer 502′ may be carried outvia a wet etching process to form the active layer 400, the third metallayer 501 a, the fourth metal layer 501 b and the second metal oxidelayer 502 (as shown in FIGS. 1 to 3).

The etchant utilized in the wet etching process may be substantiallyidentical to the etchant utilized in forming the first wiring layer 200.

In this manner, the second wiring layer 500 and the active layer 400 maybe formed. The specific shapes, arrangements and physical properties ofthe second wiring layer 500 and the active layer 400 have been describedabove, therefore, the redundant description will be omitted.

Although not shown in the drawings, after forming the second wiringlayer 500, an insulating layer made of an insulating material, a pixelelectrode, and the like may be formed to fabricate a wire substrate fordisplay devices.

Hereinafter, the present disclosure will be described in more detailwith reference to specific experimental examples.

Experimental Example 1 Measurement of Reflectivity According to TantalumContent

A single titanium layer was deposited on a glass substrate at thethickness of approximately 200 Å. Subsequently, a single copper layerwas deposited on the titanium layer at the thickness of approximately6,000 Å. Subsequently, a Mo_(x)Ta_(y)O_(z) target material having thecontent of tantalum of 1.0 at % among the metal atoms was prepared. Thetarget material was deposited to a thickness of about 400 Å on thecopper film by sputtering to prepare a triple-layer stack.

Subsequently, a photosensitive mask pattern was formed on thetriple-layer stack, and the etchant was applied onto it. The etchantutilized includes peroxysulfate as the main component for etching andfurther includes an organic acid, a fluorine-containing compound, and acyclic amine compound. It took 171 seconds until the etching has beencompleted. Here, the etch time was 171 seconds.

After the etchant was applied, images of the residual stack pattern werecaptured utilizing a microscope. In addition, the tip length of theMo_(x)Ta_(y)O_(z) layer of the stack pattern and the reflectivity at thetop of the stack pattern were measured. The reflectivity was measured inthe visible wavelength band.

Experimental Example 2 Measurement of Reflectivity According to TantalumContent

A triple-layer stack was prepared in substantially the same manner as inExperimental Example 1 except that the content of tantalum in the targetmaterial was 2.0 at %. Then, the etchant was applied onto thetriple-layer stack. The etch time was 194 seconds.

Subsequently, images were captured by a microscope, and the tip lengthand reflectivity of the Mo_(x)Ta_(y)O_(z) layer were measured.

Experimental Example 3 Measurement of Reflectivity According to TantalumContent

A triple-layer stack was prepared in substantially the same manner as inExperimental Example 1 except that the content of tantalum in the targetmaterial was 4.0 at %. Then, the etchant was applied onto triple-layerstack. The etch time was 295 seconds.

Subsequently, images were captured by a microscope, and the tip lengthand reflectivity of the Mo_(x)Ta_(y)O_(z) layer were measured.

Experimental Example 4 Measurement of Reflectivity According to TantalumContent

A triple-layer stack was prepared in substantially the same manner as inExperimental Example 1 except that the content of tantalum in the targetmaterial was 6.0 at %. Then, the etchant was applied onto triple-layerstack. The etch time was 171 seconds.

Subsequently, images were captured by a microscope, and the tip lengthand reflectivity of the Mo_(x)Ta_(y)O_(z) layer were measured.

FIG. 14 shows microscopic images of the stack patterns formed accordingto Experimental Examples 1 to 4.

Referring to FIG. 14, it can be seen that the triple-layer stacksincluding the Mo_(x)Ta_(y)O_(z) layer were etched altogether to formpatterns. The taper angle of the stack pattern according to ExperimentalExample 1 was approximately 72 degrees, the taper angle of the stackpattern according to Experimental Example 2 was approximately 69degrees, the taper angle of the stack pattern according to ExperimentalExample 3 was approximately 85 degrees, and the taper angle of the stackpattern according to Experimental Example 4 was approximately 80degrees. In this specification, the term ‘taper angle’ means an angle ofinclination between a bottom surface of a pattern and a side surface ofthe pattern.

FIG. 15 is a graph showing tip lengths of Mo_(x)Ta_(y)O_(z) layersaccording to Experimental Examples 1 to 4.

Specifically, the tip length of the Mo_(x)Ta_(y)O_(z) layer of thepattern according to Experimental Example 1 was approximately 0.05 μm,and the tip length of the Mo_(x)Ta_(y)O_(z) layer of the patternaccording to Experimental Example 2 was approximately 0.07 μm. Inaddition, the tip length of the Mo_(x)Ta_(y)O_(z) layer of the patternaccording to Experimental Example 3 was approximately 0.16 μm, and thetip length of the Mo_(x)Ta_(y)O_(z) layer of the pattern according toExperimental Example 4 was approximately 0.20 μm. Here, it can be seenthat the tip length gradually increases as the tantalum content in theMo_(x)Ta_(y)O_(z) layer increases. In particular, comparing ExperimentalExample 2 with Experimental Example 3, it can be seen that the length ofthe tip is increased more than twice as the tantalum content exceeds 2.0at %, and accordingly it is difficult to control the etched surface(e.g., the shape of the etched surface).

FIG. 16 is a graph showing the light reflectivity of the stack patternsaccording to Experimental Examples 1 to 4 measured in the visiblewavelength band.

Referring to FIG. 16, it can be seen that the light reflectivity of thestack pattern according to Experimental Example 2 has the minimum value.That is, it is to be noted that the light reflectivity does not changelinearly with increasing or decreasing tantalum content in theMo_(x)Ta_(y)O_(z) layer. It can be seen that the light reflectivity ofthe stack pattern has the minimum value when the tantalum content in theMo_(x)Ta_(y)O_(z) layer is between 1.0 at % and 2.0 at %.

The average of light reflectivities of the stack patterns according toExperimental Examples 1 to 4, and the light reflectivity with respect tolight having the wavelength of 550 nm are shown in Table 1 below:

TABLE 1 Light Reflectivity (%) Average Light Light Reflectivity atReflectivity (%) Wavelength of 550 nm Experimental Example 1 8.61 5.34Experimental Example 2 8.41 4.72 Experimental Example 3 8.94 5.47Experimental Example 4 8.46 8.65

Experimental Example 5 Comparison of Etching Characteristics Accordingto Etchant Components

A triple-layer stack was prepared in substantially the same manner as inExperimental Example 2 except that an etchant containing sulfuric acidas the main component for etching was utilized. Then, the etchant wasapplied onto the thriple-layer stack.

Images were captured utilizing a microscope to observe the etchedlayers.

Experimental Example 6 Comparison of Etching Characteristics Accordingto Etchant Components

A triple-layer stack was prepared in substantially the same manner as inExperimental Example 3 except that an etchant containing sulfuric acidas the main component for etching was utilized. Then, the etchant wasapplied onto the triple-layer stack.

Images were captured utilizing a microscope to observe the etchedlayers.

Experimental Example 7 Comparison of Etching Characteristics Accordingto Etchant Components

A triple-layer stack was prepared in substantially the same manner as inExperimental Example 4 except that an etchant containing sulfuric acidas the main component for etching was utilized. Then, the etchant wasapplied onto the triple-layer stack.

Images were captured utilizing a microscope to observe the etchedlayers.

Experimental Example 8 Comparison of Etching Characteristics Accordingto Etchant Components

A triple-layer stack was prepared in substantially the same manner as inExperimental Example 2 except that an etchant containing phosphoricacid, nitric acid and acetic acid as the main components for etching wasutilized. Then, the etchant was applied onto the triple-layer stack.

Images were captured by utilizing a microscope to observe the etchedlayers.

Experimental Example 9 Comparison of Etching Characteristics Accordingto Etchant Components

A triple-layer stack was prepared in substantially the same manner as inExperimental Example 3 except that an etchant containing phosphoricacid, nitric acid and acetic acid as the main components for etching wasutilized. Then, the etchant was applied onto the triple-layer stack.

Images were captured utilizing a microscope to observe the etchedlayers.

Experimental Example 10 Comparison of Etching Characteristics Accordingto Etchant Components

A triple-layer stack was prepared in substantially the same manner as inExperimental Example 4 except that an etchant containing phosphoricacid, nitric acid and acetic acid as the main components for etching wasutilized. Then, the etchant was applied onto the triple-layer stack.

Images were captured utilizing a microscope to observe the etchedlayers.

Experimental Example 11 Comparison of Etching Characteristics Accordingto Etchant Components

A triple-layer stack was prepared in substantially the same manner as inExperimental Example 2 except that an etchant containing peroxide as themain component for etching was utilized. Then, the etchant was appliedonto the triple-layer stack.

Images were captured utilizing a microscope to observe the etchedlayers.

Experimental Example 12 Comparison of Etching Characteristics Accordingto Etchant Components

A triple-layer stack was prepared in substantially the same manner as inExperimental Example 3 except that an etchant containing peroxide as themain component for etching was utilized. Then, the etchant was appliedonto the triple-layer stack.

Images were captured utilizing a microscope to observe the etchedlayers.

Experimental Example 13 Comparison of Etching Characteristics Accordingto Etchant Components

A triple-layer stack was prepared in substantially the same manner as inExperimental Example 4 except that an etchant containing peroxide as themain component for etching was utilized. Then, the etchant was appliedonto the triple-layer stack.

Images were captured m utilizing a microscope to observe the etchedlayers.

FIG. 17A shows microscopic images according to Experimental Examples 5to 7. FIG. 17B shows microscopic images according to ExperimentalExamples 8 to 10. FIG. 17C shows microscopic images according toExperimental Examples 11 to 13.

Referring to FIG. 17A, it can be seen that the triple-layer stacks wereoverly etched and could not form a pattern when the etchant containingsulfuric acid as the main component for etching was utilized. Referringto FIG. 17B, it can be seen that the layers were unetched when theetchant containing phosphoric acid, nitric acid and acetic acid as themain components for etching was utilized. Referring to FIG. 17C, it canbe seen that the triple-layer stacks were overly etched and could notform a pattern when the etchant containing peroxide as the maincomponent for etching was utilized.

Therefore, it can be seen that the etchant containing the peroxysulfateutilized in Experimental Examples 1 to 4 exhibited excellent etchingproperties over the other etchants with respect to the triple-layerstack including the Mo_(x)Ta_(y)O_(z) layer.

Experimental Example 14

A simulation was carried out to see light reflectivity according to thethickness of the Mo_(x)Ta_(y)O_(z) layer having the content of tantalumof 2.0 at % when the thickness of the titanium layer was 200 Å and thethickness of the copper layer was 6,000 Å. The thickness of theMo_(x)Ta_(y)O_(z) layer was measured at every 50 Å from 50 Å to 1200 Å.Light reflectivity was measured in the visible wavelength band.

FIG. 18 is a graph showing simulation results according to ExperimentalExample 14.

Referring to FIG. 18, it can be seen that the light reflectivity of thetriple-layer stack pattern varies depending on the thickness of theMo_(x)Ta_(y)O_(z) layer.

Specifically, when the thickness of the Mo_(x)Ta_(y)O_(z) layer was 50Å, the reflectivity with respect to light having the wavelength of 550nm was approximately 55.1%. In addition, when the thickness of theMo_(x)Ta_(y)O_(z) layer was 250 Å, the reflectivity with respect tolight having the wavelength of 550 nm was approximately 14.0%. On theother hand, when the thickness of the Mo_(x)Ta_(y)O_(z) layer was 300 Å,the reflectivity with respect to light having the wavelength of 550 nmwas approximately 7.2%, which is significantly lowered. Further, whenthe thickness of the Mo_(x)Ta_(y)O_(z) layer was 400 Å, the reflectivitywith respect to light having the wavelength of 550 nm was approximately1.8%, which is the lowest.

In addition, when the thickness of the Mo_(x)Ta_(y)O_(z) layer is 550 Å,the reflectivity with respect to light having the wavelength of 550 nmwas approximately 7.5%. On the other hand, as the thickness of theMo_(x)Ta_(y)O_(z) layer is increased to 600 Å, the reflectivity withrespect to light having the wavelength of 550 nm was increased (e.g.,abruptly increased) to approximately 10.7%. When the thickness of theMo_(x)Ta_(y)O_(z) layer is 750 Å or more, the reflectivity with respectto light having the wavelength of 550 nm converged to approximately 20%.

While the present invention has been particularly illustrated anddescribed with reference to exemplary embodiments thereof, it will beunderstood by those of ordinary skill in the art that various suitablechanges in form and detail may be made therein without departing fromthe spirit and scope of the present invention as defined by thefollowing claims, and equivalents thereof. The exemplary embodimentsshould be considered in a descriptive sense only and not for purposes oflimitation.

What is claimed is:
 1. A display device comprising: a first base; and afirst wiring layer on the first base, the first wiring layer comprisinga conductive layer and a metal oxide layer on the conductive layer,wherein the metal oxide layer comprises molybdenum (Mo), tantalum (Ta),and oxygen (O), wherein the conductive layer comprises a first metallayer on the first base, and a second metal layer between the firstmetal layer and the metal oxide layer, wherein the second metal layerhas a higher electrical conductivity than the first metal layer, andwherein a thickness of the second metal layer is greater than athickness of the first metal layer.
 2. The display device of claim 1,wherein the conductive layer is opaque, and wherein a light reflectivityof the metal oxide layer is less than a light reflectivity of a toplayer of the conductive layer in contact with the metal oxide layer. 3.The display device of claim 1, wherein the conductive layer is betweenthe first base and the metal oxide layer, and wherein the metal oxidelayer is a top layer of the first wiring layer.
 4. The display device ofclaim 1, wherein the conductive layer is between the first base and themetal oxide layer, and wherein a reflectivity of the first wiring layerwith respect to light that has a wavelength of 550 nm and is incident ina direction from an upper side to a lower side is equal to or less than6.0%.
 5. The display device of claim 1, wherein the first metal layercomprises a refractory metal, and wherein the second metal layercomprises copper, silver, aluminum, or an alloy thereof.
 6. The displaydevice of claim 1, wherein the second metal layer is in contact with thefirst metal layer and the metal oxide layer, wherein a thickness of themetal oxide layer is greater than the thickness of the first metal layerand is less than the thickness of the second metal layer, and whereinthe thickness of the metal oxide layer ranges from 300 to 550 Å.
 7. Thedisplay device of claim 1, wherein the second metal layer is in contactwith the first metal layer, and wherein a width of a surface of thefirst metal layer facing the second metal layer is greater than a widthof a surface of the second metal layer facing the first metal layer. 8.The display device of claim 1, wherein a side wall of the metal oxidelayer protrudes from a side wall of the conductive layer to form a tip.9. The display device of claim 1, further comprising: a second wiringlayer partially overlapping with the first wiring layer and insulatedfrom the first wiring layer, the second wiring layer comprising aconductive layer and a metal oxide layer stacked on one another, whereinthe metal oxide layer of the second wiring layer comprises MoxTayOz,wherein a content of tantalum is equal to or less than 2.0 at % based ona total number of metal atoms.
 10. The display device of claim 9,further comprising: a semiconductor material layer between the first andsecond wiring layers, wherein the first base comprises a glasssubstrate, and wherein the conductive layer of the first wiring layer isdirectly on the first base.
 11. The display device of claim 9, whereinthe first wiring layer comprises a gate signal wire extending in a firstdirection and a sustaining electrode, and wherein the second wiringlayer comprises a data signal wire extending in a second directioncrossing the first direction.
 12. The display device of claim 11,wherein the conductive layer of the second wiring layer comprises athird metal layer, and a fourth metal layer between the third metallayer and the metal oxide layer, wherein the thickness of the firstmetal layer is greater than a thickness of the third metal layer, andwherein the thickness of the second metal layer is greater than athickness of the fourth metal layer.
 13. The display device of claim 11,wherein a side wall of the metal oxide layer protrudes from a side wallof the conductive layer to form a tip in each of the first wiring layerand the second wiring layer, and wherein a length of the tip of themetal oxide layer in the second wiring layer is greater than a length ofthe tip of the metal oxide layer in the first wiring layer.
 14. Thedisplay device of claim 11, further comprising: a light-shielding memberon the second wiring layer and having a line shape extended in the firstdirection, wherein the sustaining electrode comprises a portion extendedin the first direction and a portion extended in the second direction,wherein the gate signal wire completely overlaps with thelight-shielding member, wherein the sustaining electrode partiallyoverlaps with the light-shielding member, wherein at least a part of theportion extended in the second direction does not overlap thelight-shielding member, and wherein the data signal wire partiallyoverlaps with the light-shielding member, wherein at least a part of thedata signal wire does not overlap with the light-shielding member.